MSD 75643-HC High-Current Solid-State Relay Features:

• Includes (2) mounting tabs, (2) mounting bolts, (2) nuts, and (6) washers
• Designed for use with electric fans, water pumps, nitrous solenoids, auxiliary lighting, and more
• (4) Independent channels that operate at 35 Amps each continuous current (140 total)
• Each channel can be run in parallel for devices needing more than 35 Amp single-channel rating
• Built-in protection from over-temperature, short-circuiting, and current overload
• Pulse Width Modulation (PWM) signal compatibility to control 150-hertz max output rate and a 50 to 90-percent duty cycle
• Single-wire activation by using either power or ground
• Can be rotated 90-degrees for various mounting configurations
• Max on-time amperage ratings (per channel):
  • 35 Amps: Continuous
  • 40 Amps: 3 hours
  • 45 Amps: 30+ minutes
  • 50 Amps: 12 minutes
  • 60 Amps: 35-seconds
  • 80 Amps: 12-seconds
  • 100 Amps: 8-seconds

MSD 75643-HC High-Current Solid-State Relay Note:

• Recommended wire gauge usage:
  • Main input battery positive: 2 AWG
  • Channel 1-4 outputs: 8 AWG
  • 12 V and ground activation wires: 18-22 AWG

FAQ

What are the two types of solid state relays?

• Zero-crossing relays: Activates when the AC voltage crosses zero.
• Random turn-on relays: Triggered at any point in the AC cycle.

What current does a solid state relay control?

• MSD 75643-HC manages up to 20 amps of current effortlessly.
• It reliably controls varying current loads for optimal performance.

What is a solid state over current relay?

• The MSD 75643 is an over current relay safeguarding against excessive electrical flow.
• Monitors and prevents high current, ensuring system safety.

What is the difference between SSR and mechanical relay?

• MSD solid state relays (SSRs) like the 75643-HC use semiconductors for switching, offering faster response and longer lifespan.
• Unlike mechanical relays, they have no moving parts, reducing wear and tear.